Compare gas versus electric water heaters to find which type is the best for your home. This article helps you understand the differences between heaters powered by natural or propane gas and electricity, with the benefits, pros, and cons.
The main factors to consider when choosing the water heater for residential applications are selecting the fuel type - gas or electric, and how it stores water (tank vs tankless). When selecting the type of the energy source you should also consider the fuel availability and its costs, size of the unit and the energy efficiency.
There are several well-known manufacturers and brands of water heaters in North America, such as Rheem, AO Smith, Bradford White, State, Reliance, Kenmore, John Wood and their models are mainly fueled by gas and electricity.
Electricity is widely available in North America while natural gas and propane less. If you have more than one fuel type available in your area, it is a good idea to compare its costs.
Gas-powered water heaters use less energy and cost less to operate than electric models, which come with the higher energy efficiency.
Initial cost when buying the electric type generally cost less than when buying a gas water heater, and the installation costs are lower. In a case of the gas-powered units, you must provide venting system and gas supply line, which makes them less safe than electric models, which also require less maintenance.
Electric units can be installed almost anywhere inside the house, especially point-of-use and tankless water heaters, while gas-powered models require proper location. They need or might need a vent system, chimney, proximity of the outside wall, electricity to power vent models... Basically, all these requirements increase the price.
If the natural gas is not available in your area, the other option is to use propane gas, which is cheaper than electricity, but it requires the storage and regular fuel delivery, which contributes in higher costs.
Energy Factor or EF rating is often used when choosing the water heater. If the required EF value is reached, the water heater is compliant with the Energy Star requirements, which brings the operating costs down and at the same time helping the environment. So the higher EF, the more efficient water heater is, but...
The energy factor of the gas water heaters is found from 0.57 to over 0.9 for condensing models, where the EF of 0.67 and higher meet the Energy Star standards. On the other side, electric units have the EF over 0.9 but are not Energy Star approved. The only electric powered heaters that meet the requirements are electrically operated heat pumps. This type of the electric water heaters has lower energy cost than gas-fired, because of the higher efficiency, which can go over 2.0.
The advanced type of gas heaters uses the gas control valve that provides more reliable and accurate performance, with the better temperature control and faster hot water recovery. Such gas valves come with the LCD display or LED diodes, which informs its users about the status, errors and other useful info. Models that are direct vent and are using the thermopile do not need the electric power, which is not the case with the electric units, because - no electricity no hot water.
The only electric units with the advanced electronics (smart), such as those found on gas models, are heat pumps.
Gas-powered water heaters tend to have higher flow rates than electric ones but can waste energy if they are equipped with the pilot light.
When comparing gas versus electric water heaters and reviewing its parts, it can be noticed that gas models are more complex, therefore more expensive. They both use elements such as the anode rod, ceramic/glass lining, dip tube, TPR valve, but the main difference is how they heat water. If planning to install the electric tankless water heater in the old house, it might be required to replace the whole wiring and the electric panel so the unit can deal with the higher amps.
Gas units require a gas line, gas control valve, gas burner with the combustion chamber, pilot light or electrode, thermocouple and venting-exhaust system, while electric units require only heating elements and thermostats for heating water.
There is a greater variety of gas-powered water heaters than electric, as seen below:
Power and Power-Direct vent
Ultra Low NOx
Water heaters with the pressurized combustion chamber, such as State Premier high-efficiency model.
Hybrid that uses both tank-type and tankless technology, such as AO Smith NEXT model.
Gas units can work with the lower amounts of water in the tank as the gas burner is located at the bottom of the unit, while the electric models require the water level above the heating elements, because they can burn out, resulting in the element failure.
Final thoughts when comparing gas vs. electric water heaters...
In almost all of North America, natural gas is the most economical way for water heating, and if the gas is available in your area the recommendation is to buy a gas water heater. If gas is an issue, the heat pumps are the next pick.